I would love to have one of these, it would be super useful! No really, I'm serious! The swiping to scroll vertically AND horizontally would be super useful for me when I'm editing projects in multi-window apps like music editing programs (Logic, Ableton, heck even garageband). Zooming would be handy too. I was hoping they would come out with a product like this for a while actually, but I never actually thought they would... The touchpads (stand alone or built in) are awesome because of the gestures, since they allow for quick and smooth interfacing and control of your programs (as far as scrolling and zooming and whatnot go). A mouse is, however, more accurate as a pointer tool, and the right click functionality is better too (except apple mice have always had crappy right clicking (since it won't register a right click if your finger is still touching the left side of the mouse)). Anyways, this is an awesome supplementary tool. Not cheap though... but of course, that's apple for you!